Question

question on integration problem

Answer 1

\[1\div(\sqrt{(4-x))}dx\ ]
\[-\int\limits_{?}^{?} 1\div \sqrt{w} dw = -2\sqrt{w} +C = -2\sqrt{(4-x} + C\]

Those are the steps we did in class and i understand all of it except the -2. Can someone explain where that came from please?

And i did it with substitution where w = 4 - x dw = -dx

Answer 2

1/sqrt(w) = w^-1/2

so when you integrate you add the power by one and multiply by its inverse
inverse of -1/2 is -2

Answer 3

thanks